THE HIGH LIFE At the end of a race, the legendary University of Oregon runner Steve Prefontaine would appear weirdly comatose. The muscles in his legs would strain into a million ropy fibers, but his face would turn to putty. It was like he was watching golf. This involuntary escape from otherworldly pain-the runner's high-is what every endurance athlete, professional or amateur, aims to achieve. For long-distance runners in particular, this enviable trance is not unlike yielding to a seductive drug-an elusive experience that, could you bottle it, you'd be doing most of your running to the bank.

It's natural to speak of this state of mind as a form of detachment, a lapse or an escape into an ethereal cocoon. That's not exactly the case, though. The mind and body under such circumstances aren't disengaging so much as blending in a way that's transcendent and calming. Who knows how anyone ever reaches this mystical apex? Who really grasps the inner mechanics of such an unexpected form of euphoria? I suspect that there are as many paths to this state of being as there are people fortunate enough to discover it.

For me, I learned that this kind of high could also be experienced by being vegan. In 2007, after nearly thirty-eight years, I stopped eating animals. Veganism and running, in turn, became complementary sides of my evolving identity, inseparable and mutually reinforcing phenomena that have worked me into a more whole, or at least less fragmented, person than I once was. Before veganism, running was something I did. After veganism, it was an essential part of who I'd become: a humble agent of change.

A CAVEAT: As an athlete I'm nothing to get excited about. I'm persistent, for sure, but certainly no star. In the course of running more than twenty-five marathons and several ultramarathons, and with the benefit of almost twenty-five years of running experience, I'm in a position of doing a few useful things: I can weave my own running narratives, identify my own lessons learned, appreciate my own trips into "runner's high" transcendence, and lick my own self-inflicted wounds. I've been running almost every day for nearly two-thirds of my life; I have stories about running and, like most runners, I enjoy telling them. All that said, as a runner, I am, on a good day, an average talent.

Another caveat: While veganism was the defining hinge in my personal history as a runner, I'm in no position to proselytize (who really is?). Which is to say, I'm not suggesting that an athlete must go vegan to achieve any benefits. That would be crazy. And obnoxious. And possibly even counterproductive. The vast majority of addicted runners I know-and I'm talking about people who will happily scrape themselves out of bed at 4:30 a.m. to run twenty miles in eight-degree weather-are running with incisors, and they intend to use them much as their hominid ancestors did. Most runners I know rip flesh from bone with enthusiasm. Indeed, perhaps touched with a little paleofantasy, they are perfectly happy to tap into their inner caveman, chase down a feral pig, build a fire, and eat the beast without care or compunction about ethics or nutrition.

I just know that, as a runner, I can speak truth to one reality: my own. For me, running and eating plants have become not only necessarily intertwined, but mutually reinforcing and transformative endeavors that empower me to rage in the best way I can over what it means to not only live, run, and eat, but to stand up for the most vulnerable in a quest for justice. These endeavors, I've since dis- covered, are worth a commitment. They are worth sacrifice. How they were merged is, in many ways, the story of how I became the person I am.

MY INITIAL AWAKENING as a long-distance runner happened suddenly. It was a crisp fall late afternoon in 1988. I was in college in Washington, D.C., and had just bombed a physics exam, effectively dashing whatever slim chance I ever had of getting into medical school. I dressed up for my normal three-mile run and felt overcome emotionally-which is to say I basically felt like a loser. All my insecurities were coalescing in a dark place. Under a sky that had exploded into a kaleidoscope of blue and orange, I left the house and, on cobblestone streets, passing the townhouses of the power elite, did my standard three-mile run. Usually, my thoughts would be ironed out by the time I finished this ritualistic loop around Georgetown. But not this time. This time I remained a mess.

So I kept running. From Georgetown I headed down to the Kennedy Center, over to the Lincoln Memorial, and across the Mall to the Capitol. By then it was dark and the city sparkled. My gloominess started to lift. The simple act of moving through space in the center of a flickering city, breathing steadily, mollified me into an acceptance of a medical school–free future. I crossed the 14th Street Bridge into Virginia, ran along the parkway, cut across onto Roosevelt Island, and then headed over the Key Bridge back onto the cobblestone playground of Georgetown. Certainly, there were other vocations to pursue. I could drive a cab or be a bicycle messenger. My mind did somersaults. The coup de grace was to bolt up the famed "Exorcist Steps," a fierce Everest-like incline off M St. made famous in the unnerving 1973 horror movie I couldn't finish because it scared me so badly. But my worries were gone. Even better, I was high.

I guessed I'd run about seventeen miles. At home, I grabbed an icy beer and gulped it down in the hot shower. Now I was better than high. And I was also hooked. Over the following winter and into spring I started to explore the city's extensive trail system (Rock Creek Park), ran through parts of town I'd never explored (Hayne's Point, Capitol Hill, Arlington), and I even found a friend to do longer weekend runs with, eventually reaching into the sixteen to twenty-mile range every Saturday morning, followed by a heaping plate of eggs and sausage.

My roommates, a group of artists and writers who elevated laziness to an art form, took to calling me "Mr. Squirrel," suggesting that I was running around the woods of D.C. gathering nuts and berries for the impending winter. One friend, a painter with a special talent for inactivity, suggested that they hook me up to a generator so I could produce renewable energy. I began to shed weight. One Christmas all I received from everybody I knew was running clothes.

I ran the San Francisco Marathon in 1992. Knowing what I know now, this was a colossally stupid choice for a first marathon. Even the hills had hills. But it wasn't quite disastrous enough to ruin the idea of running marathons for good, despite the fact that I couldn't walk down stairs for two weeks after the race. Diet wasn't helping my cause. Eating at this time in my life was a remarkably passive-aggressive experience. As a young man running forty miles a week, then fifty, I'd not only eat whatever you put in front of me, I'd have seconds. And thirds. It seemed the more I ate the thinner I became. So why care? I recall looking in the mirror at my body in the basement of my D.C. home and noting that, for the first time since pre-pubescence, my ribs were poking through my torso. And I was consuming food like a Dumpster.

Essentially, to the extent that I ever pondered it, eating was an input/output experience. It was fuel. I either burned it or evacuated it. Food was functional. No more or less. This remained the case for well over a decade, and it was during this decade that my signature weakness as a marathoner became depressingly clear: I was completely useless after twenty miles. No energy. No runner's high. No transcendence. Nothing but pain.

This is a rather intractable problem for a marathoner. Not only because a marathon is 26.2 miles, but, as they say, a marathon is a twenty-mile warm-up for a 6.2 mile run. Whether on training runs or actual races, I bonked and crumbled and gorked and choked (choose your term) after twenty. Every time. And I'm not talking about discomfort. I'm talking pain that was metaphysical in nature, otherworldly, and not even worth the tears. They call it a wall, but that's bullshit. You can climb a wall. Or build a door into it. Or slump against it. Worse, it would take me at least ten days to feel normal again after a race.

In 2007, after a score of marathons with times that wouldn't budge, I experienced a different kind of pain. I watched a video of a calf being taken from his mother just after birth. It was one of the worst experiences of my life. How a person makes it through more than three decades without encountering such an event is a testament to the power of modern culture to sanitize the violence of reality. So I watched this clip. Then I watched it again. One more time.

As a seasoned academic (at this point I had become a historian instead of a doctor or cab driver or bike messenger) I knew I was supposed to think and deliberate and avoid reaching hasty conclusions. Indeed, I was supposed to resist sentimentality and be objective and keep a cool head. But I also knew that, as an academic, I was perfectly capable, as most academics are, of thinking myself into a drooling stupor, of having the emotional makeup of a stone, of abjectly failing to be human. So I said no more. In my office, I stood up, looked out the window, and literally said to myself, "No more." I thereby became a vegan with the same epiphanic concentration of conviction that I became a runner. And as with running, I've never bothered to reconsider.

TO ME, THE saying that life becomes a utopia after going vegan is the same sort of cheesy propaganda as "Got milk?" or "Where's the beef?" Veganism can be a big pain in the ass. Eating out becomes a small nightmare. Dinner party invitations decrease. Airports send you into crisis mode. The entire country of France looks at you funny. Your Italian grandmother thinks you're mentally ill. If a vegan tells you that it's easy being vegan, and he has anything resembling a social life or doesn't live in Vegantown, U.S.A., don't believe him. Not a word.

But, no exaggeration here, veganism saved my running. Eating a nutrient-rich plant-based diet had a remarkable impact on my post-twenty-mile dilemma. Most notably I was now regularly zooming past the twenty-mile mark feeling better than I did at mile ten. I began to do ultramarathons and was even feeling strong past thirty miles. Even more befuddling, after bombing my body with a post-run bowl of quinoa, amaranth, blueberries, cashews, and agave syrup, followed up by a banana-cocoa powder smoothie, I was recovering so quickly I could go out the next day without soreness. Recall: before veganism it would take about two weeks for my legs to feel normal. Now it was taking less than a day. So, no, life didn't become a utopia, but, for the first time, I was running daily with pure joy.

Buttressed by veganism, my running-which had resumed giv- ing me a high-did something unpredictable and wonderfully generous. It turned around and began the long and slow process of making my personal veganism political. I began to whisper some of my ideas into print. Then I got a bit louder. Before long, I was yelling into the pages of mainstream magazines and newspapers that, to my surprise, wanted to hear what I had to say about animal rights and ethical veganism and moral consistency. In a twist that's even more wonderful and liberating, this activism began to inform my running. It was then that everything coalesced into something.

Let me try and explain this relationship. First: the running. Long-distance running-especially when you can do it in an ethereal frame of mind-is personal and political, but even more, it's transcendental. You transcend "normal" behavior as well as your own expectations. Over time, this serial transcendence plateaus at a different idea of "normal." Through this empowering process, you continually recalibrate your identity. You constantly create new conceptions of what's possible and those new conceptions become part of you and you become much more interesting to yourself than you ever were.

The key is this: You become more involved with the world as an agent of change. You rage a bit against conventions. And this entire process is modeled. Others witness it; many are pissed and jealous and hate you. But many others are moved by it-and they change for the better. In this intensifying two-step of empowerment and transcendence, you are a public model, whether you think so or not. When you start running seventy or eighty miles a week, the people around you eventually take notice and become curious about you as a person with thoughts and goals and habits. It's an exceptional thing, mainly because you're not seeking anything but inner peace. But you become a leader-ideally, a humble one.

Second: the vegan part. A very similar scenario-this internalizing, identifying, witnessing, and modeling-happens with vegan advocacy. My chances of convincing a non-runner to run by declaring "Run!" are the same as convincing a non-vegan to go vegan by declaring "Go vegan!" Basically zero. Yes, you have to make your case, and there are a million ways to do it, but ultimately you have to do so while putting yourself out there, by allowing yourself, although scared to death, to be witnessed. It's risky, and people will scream at you, but there's really no other choice if you want everything to become something.

A long-distance runner cannot hide her running identity any more easily than a vegan advocate can hide his vegan identity. Nor should they hide it. Exposure has its costs, for sure, but the rewards are sublime; just ask any ethical vegan or self-identified runner. In these ways, both long-distance running and ethical veganism etch positive standards-personal and political-into the pantheon of unrealized possibilities. To an extent, to be a vegan runner is to be the humblest of revolutionaries.

A revolutionary mentality, at its essence, demands several qualities: the ability to waver between individualism and community, the ability to not care when people you admire, love, or disagree with you (or end up hating you), the ability to choose peace over force whenever possible, and the ability to admit when you're wrong and not gloat when you're right. And, in doing all this, you will never feel more right.

I think running and veganism, when brought together, have a spiritual way of imparting and nurturing the emotional preconditions of many revolutionary-minded qualities. I won't go into precisely how for each, but I will say this: In general, running and veganism teach humility; greed for what's good; inestimable self-assurance; and a deep sense of what really matters. These attributes strike me as critical for any effective revolutionary mentality, whether collective or individual. Animals will never thrive in a human culture of arrogance and indifference.

SINCE BECOMING A vegan, I often have to stop in the middle of a run because the force of the experience overwhelms me so. It's as if you cannot be more present in the world at that moment. And the beauty is, you don't need to do anything. Just exist. And run. And not eat animals. Every distraction evaporates and you feel completely, fully alive and stunned at once.

This happened to me while running trails alone in the mountains around Eugene, Oregon-Steve Prefontaine's hometown- about three years ago. It was an impossibly crisp day. My run began in the city and, as I dealt with traffic and noise, my mind started to clutter with the data of daily life: work, bills, deadlines. I was dealing with a sore foot at the time and feeling sorry for myself as I left the city behind and entered the woods. When I hit elevation, my breathing picked up. As I reached about twelve miles, I turned a corner on the trail. Next thing I knew, out of nowhere, I was seized by the beauty of the forest around me, by the calm that fell over me, by the empowerment that characterized my life. I found myself, a vegan-ultramarathoning-revolutionary-writer-activist living the high life, leaning against a Douglas Fir tree, as hopeful and happy as I'd ever been in a world marked by pain.